Topical compositions of urea and ammonium lactate

Abstract

Pharmaceutical, cosmetic and cosmeceutical compositions for topical application, containing, as active ingredients, urea and / or derivatives thereof and alpha-hydroxy acid and / or an ammonium salt thereof, such as ammonium lactate, processes of manufacturing same and use of same in the treatment of medical and cosmetic skin and scalp conditions.

Description

RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 10 / 850,461 filed May 21, 2004, which claims the benefit of U.S. Provisional Patent Applications Nos. 60 / 494,579 filed Aug. 13, 2003, 60 / 494,581 filed Aug. 13, 2003, 60 / 510,554 filed Oct. 14, 2003 and 60 / 527,279 filed Dec. 8, 2003, the contents of which are hereby incorporated by reference in their entirety.FIELD AND BACKGROUND OF THE INVENTION [0002] The present invention relates to novel pharmaceutical, cosmetic and cosmeceutical compositions for topical application, and their use in the treatment of medical, cosmetic and cosmeceutical conditions such as dry skin and / or scalp. [0003] Dry skin is a common condition associated with a plurality of disorders and frequently requires therapeutic intervention. [0004] Dermatologists often call dry skin in later life “xerosis” or “ichthyosis”. Xerosis is a term used to describe abnormal skin dryness. Ichthyosis is a term used to described a gr...

AI Technical Summary

Benefits of technology

"The present invention provides a stable and efficient pharmaceutical, cosmetic, or cosmeceutical composition for the treatment of various dermatological disorders such as dry skin, scalp, and acne. The composition contains urea and / or a derivative thereof, an alpha-hydroxy acid and / or a salt thereof, and a carrier. The concentration of urea and / or the derivative thereof is greater than 5 weight percentages of the composition, and the concentration of ammonium lactate is greater than 5 weight percentages of the composition. The composition can be in the form of a cream, ointment, paste, gel, lotion, milk, suspension, aerosol, spray, foam, shampoo, hair conditioner, serum, swab, pad, or soap. The composition can also contain additional active ingredients such as antibiotic agents, antimicrobial agents, anti-acne agents, antifungal agents, anti-inflammatory agents, steroidal anti-inflammatory agents, non-steroidal anti-inflammatory agents, anesthetic agents, antipruriginous agents, antioxidants, chemotherapeutic agents, antidepressants, antihistamines, vitamins, hormones, and antidandruff agents. The composition has a pH value of about 5.0 to about 8.0."

Problems solved by technology

However, these commercial preparations are disadvantageous as they are characterized by low absorption and high stickiness.

Although lactic acid is a known hydrating agent, its concentration in this preparation is relatively low and therefore provides no additive hydrating effect.

Nevertheless, topical formulations containing high concentrations of urea suffer many disadvantages.

Such a pH value is much higher than that of the natural skin (about 5.5), and may therefore cause irritations when applied.

Moreover, topical application of formulations that contain high urea concentrations are typically associated with an unpleasant odor of ammonia, formed by the decomposition of urea, stickiness, and white stains that remain on the skin and clothing after the evaporation of the solvent.

Hence, although both urea and ammonium lactate have been shown to act as highly efficient hydrating agents, and thus may serve as potent agents for treating dry skin conditions, the presently available topical formulations that comprise high concentrations of either urea or ammonium lactate suffer severe limitations.

U.S. Pat. No. 5,679,324 therefore teaches compositions that may optionally comprise urea or ammonium lactate and fails to teach compositions in which these substances are combined as active ingredients for the treatment of dry skin or scalp.

Hence, the composition disclosed in this patent application comprises low concentrations of urea and ammonium lactate and is aimed at cleansing and conditioning of hair and skin, and not for the treatment of diseased or compromised skin.

The prior art therefore teaches either compositions that comprise high concentrations of urea or ammonium lactate, which, as is discussed hereinabove, suffer severe limitations and hence are disadvantageous, or compositions that comprise a combination of urea and ammonium lactate, whereby these substances are used in relatively low concentrations and therefore do not serve as efficient active ingredients for treating dry skin and scalp conditions.

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